In life, Desta Byrd was a gorgeous woman who lit up a room. After her mysterious slaying in 1999, her beautiful face became the icon of a grassroots movement just south of Birmingham, Ala., where her friends posted billboards seeking "Justice for Desta."

Desta's supporters finally got their long-sought justice on Wednesday in a Centreville, Ala., courtroom, where Desta's husband, Jody Byrd, was sentenced to 99 years in prison for her murder.

The case sat unsolved for years, with little evidence to disprove the husband's claims that he found his wife lying next to the driveway when he got home from work on Feb. 25, 1999, dead from a single gunshot wound to the head.

Jody suggested that the 29-year-old, who worked as a benefits advisor for the Social Security Administration, was murdered in a home-invasion robbery.

But her friends' lobbying efforts led to fresh interviews with Jody, 46, during which he changed his story about how he found her. On Nov. 1, after a weeklong trial, a jury convicted Byrd of murder.

"If not for those friends never giving up, I don't know if this case would have been solved," Blount County District Attorney Pamela Casey, the special prosecutor for the case, tells PEOPLE.

While the defense did suggest that Desta had committed suicide, Casey believes Jody killed his wife because he feared she was going to leave him. He may also have been motivated to collect the insurance, Casey adds.

Among those who testified at Wednesday's sentencing hearing was Desta Byrd's mother, Vonciel Dodson, who said her daughter "never had a chance to realize her dreams because her life was cut short by her husband."

Jody's family and attorneys requested a more lenient sentence and vowed to appeal. "Jody is an innocent man. He loved Desta," said his mother, Alice Byrd.

Defense attorney Joe Basgier says his client had no motive to murder his wife.

“There were no affairs. There were no financial troubles. There's no reason that Jody would have done this,” Basgier had told the jury.

Nicole Barton, a childhood friend of Desta's who helped form Justice for Desta, said she always knew Jody was guilty, and she couldn't stop pushing for answers after police seemed to put the case on the back burner. "It was not something that I could forget," says Barton. "I couldn't let it go.”

"Today is a full victory," Casey says. "Not only did we get justice but we got the fullest sentence possible, which shows how strong circumstantial evidence was and also how egregious it was that for 14 years he manipulated the family into thinking he was the victim in this."